1. Field of the Invention
This invention relates generally to the field of concreting tools and, more, particularly to concrete edging tools.
2. Background Discussion
It is well known that after slabs of concrete are poured, for example, for sidewalks, driveways, patios, streets, and highways, and before the concrete hardens, the sharp edges of the still-wet concrete slabs are rounded off with an edging tool. This is done not only for the sake of appearance, but for safety purposes since the edges of the concrete, after the concrete has hardened may be relatively sharp and are capable of injuring anyone who happened to fall against the edges. Moreover, if the edges are left sharp, there is a tendency for the sharp edges to crack off, thereby leaving unsightly regions along the edges of the slabs.
Concrete edging tools for rounding off the edges of concrete slab (before the concrete has hardened) are usually hand-held and usually comprise a rectangle of heavy gauge sheet metal which has been bent over at 90 degrees along one edge region so as to form a short, down-turned leg or lip which is about a half inch wide and leaving a long leg which is several inches wide. The overall length of such an edging tool is usually several inches, for example, about six to eight inches. In use, such edging tools are positioned at an edge of a still-wet concrete slab, with the wide leg in contact with the exposed, upper surface of the slab. The edging tool is positioned so that the narrow leg is along the side edge of the slab. As the tool is drawn or pushed hard along the concrete, the radius portion of the tool between the short and long legs rounds off the hitherto sharp edge of the slab. The edge of the concrete slab which is rounded off in this manner may be along a side edge of the slab or may be along a wood or felt-like divider or expansion joint between adjacent concrete slabs. In other instances an edging tool may be used to create a joint in the slab along which the slab, when hardened, may preferentially crack (and not show), instead of cracking across an unscored region.
Normally such concrete edging tools are constructed having a handle for hand gripping mounted to the long leg portion of the tool. Such a handle arrangement generally requires an individual using the tool to do so from a kneeling position (assuming horizontal concrete slabs). Alternatively, the edging tool may be constructed with a long broomstick-like handle enabling the tool to be used from a standing position.
As can be appreciated, the rounding off of the edges of a concrete slab by the use of such edging tools is usually laborious, often tedious and always time consuming. Concrete sidewalks, streets, patios and other large expanses of concrete in addition to having edges along the sides of the slabs typically have numerous transverse joints, often at intervals of every few feet. In cold climates such transverse joints may be formed having a thin expansion joint constructed of a felt-like material to permit expansion and contraction of adjacent slabs of the sidewalk without cracking. In other instances concrete slabs may be divided by strips of wood, such as 2.times.4's to provide an appearance which is usually considered more attractive than a large, undivided concrete slab. In any event, such dividing of large areas of concrete into smaller areas permits the settling of the slab without cracking, each smaller slab being permitted to move somewhat relative to the other slabs by the dividing boards. In the absence of being divided in this manner into smaller concrete areas, a large area concrete slab is prone to crack due to thermal expansion and contraction and ground settling. In some instances, as mentioned above, the transverse joints between adjacent concrete slabs may, instead of divider boards or expansion strips, simply be scored lines along which the concrete sidewalk may crack, for example, due to tree roots, ground subsidence or heavy traffic, without the slab otherwise cracking and becoming unattractive.
In any event, the rounding off of edges of concrete slabs at divider boards, expansion joints and the like, requires the edging tool to be used on both sides of the divider board and expansion strip, thereby doubling the amount of edging otherwise requires. It is, therefore, a principal objective of the present invention to provide a dual concrete edging tool apparatus by means of which an adjacent pair of edged of two adjoining concrete slabs may be rounded off at the same time. Moreover, the divider board or expansion strip may be utilized as a guide for the dual edging tool apparatus.